LINQ Take

Summary: in this tutorial, you’ll learn how to use the LINQ Take() method to retrieve a specified number of elements from the beginning of a sequence.

Introduction to the LINQ Take() method

The Take() method returns a specified number of elements from the beginning of a sequence:

IEnumerable<TSource> Take<TSource>(
    this IEnumerable<TSource> source, 
    int count
)Code language: C# (cs)

In this syntax:

• TSource is the type of elements of the source sequence.
• source is the input sequence
• count is the number of elements to return.

The Take() method returns an IEnumerable<T> that contains the specified number of elements from the beginning of the source sequence.

If the count is less than or equal to zero, the Take() method returns an empty IEnumerable<T> object.

Like other extension methods, the Take() method is implemented using deferred execution. It means that the query returned by the Take() method will not execute until the elements are enumerated either by calling its GetEnumerator() method or by using a foreach.

If you want to get a range of elements, you can use the Range object instead for the second argument instead of using the integer number count:

IEnumerable<TSource> Take<TSource>(
    this IEnumerable<TSource> source, 
    Range range
)Code language: C# (cs)

The Range object specifies the range of elements to return. The range is defined by its starting and ending indexes, which can be specified from either the beginning or the end of the sequence.

In practice, you often use the Take() method with the Skip() method to skip some first elements and then take a specified number of elements.

LINQ Take() method examples

Let’s take some examples of using the LINQ Take() method.

1) Using LINQ Take() to take some elements from a sequence

The following program demonstrates how to use the Take() method to get the first three elements from an array of integers:

using static System.Console;

int[] numbers =  { 1, 2, 3, 4, 5 };

var results = numbers.Take(3);

foreach (int number in results)
{
    WriteLine(number);
}Code language: C# (cs)

Output:

1
2
3Code language: C# (cs)

We assigned the result of the Take() method to the results variable and use a foreach loop to iterate over the elements in the results sequence and write each to the console.

2) Using LINQ Take() to take some elements from a sequence using a Range object

The following program demonstrates how to use the Take() method to retrieve a range of elements from an array:

using static System.Console;

int[] numbers =  { 1, 2, 3, 4, 5 };

var results = numbers.Take(new Range(1,4));

foreach (int number in results)
{
    WriteLine(number);
}Code language: C# (cs)

Output:

2
3
4Code language: C# (cs)

In this example, we use a Range object that takes two arguments: the starting index and the ending index (exclusive).

The Range object specifies a range from index 1 to index 4, which includes elements 2, 3, and 4 of the numbers array.

Using the Range object above is equivalent to using the following Skip() and Take() methods:

using static System.Console;

int[] numbers = { 1, 2, 3, 4, 5 };

var results = numbers.Skip(1).Take(3);

foreach (int number in results)
{
    WriteLine(number);
}Code language: C# (cs)

Summary

• Use the LINQ Take() method to retrieve a specified number of elements from the beginning of a sequence or a range of elements in the sequence.